Invention relates to the field of aspirating vacuum-pneumatic transportation of bulk materials transported through pipelines under low speed and high concentrations, characterized by mass concentration coefficient from 40 to 100. Alternatively such a transport is called as dense layer vacuum transport (DLVT). The invention can be used in various fields of engineering where it is necessary to intensify the processes of bulk material transportation or perform some technological processes simultaneously with dense layer vacuum transportation. All known methods of dense layer vacuum transportation are realized due to the difference between atmospheric pressure in a place of start of moving of bulk materials through a transport pipeline and rarefication value in a place of stop of transporting of bulk materials. Effective aspiration, low power consumption in case of significant distance of transportation distinguish the dense layer vacuum transport from a large part of known methods of pneumatic transportation of bulk materials in dense layer, operations of which is based on the use of compressed air power. These methods are power-consuming, performed under the pressures much higher than atmospheric one, require compressor equipment and characterized by high speeds from 10 m/s and more, which result in dust entraining and crush of materials.
A method of pneumatic vacuum transportation of bulk materials is known (inventor's certificate USSR No 373931, MTTK B65G53/25 d/d Dec. 11, 1973), according to which prior to being delivered into a transport pipeline the bulk material is exposed to gas aeration in bottom-up direction through a porous partition.
This method disadvantage is that for bulk material aeration a system is required to be fed with compressed air, which increase the vacuum pump power consumption and speed thereof and decrease the bulk material mass concentration as well. These features do not satisfy the conditions for continuous transportation of bulk material of high mass concentration.
The closest by number of similar features to the proposed method (closest analogue) is a method for vacuum-pneumatic transportation of bulk materials (Patent RF No 2083456, MTTK B65G 53/14 d/d Oct. 7, 1997), as per which the transportation of bulk materials of high concentrations in dense layer is supported that the bulk material is vibro-fluidized in a charging device, provided that vibration acceleration value must be equal to or more than gravity acceleration. That method solved the problem of formation of bulk material dense layer on a horizontal section of transporting pipeline of short length by vibro-fluidizing method.
That method disadvantage was that due to attenuation of vibrations while bulk material distancing from inlet section, the vibro-fluidizing becomes not sufficient to support the high concentration of bulk material particles over pipeline cross-section, especially while horizontal transporting. In bulk material flow, distancing from vibro-fluidizing zone, a layering occurs and some areas of particles concentration equal to their bulk condition occur, which results in bulk material breakdowns and air breakthroughs over them, the transporter operation is broken, transportation distance and efficiency are limited.
To support the vibro-fluidizing in a transporting pipeline having vertical, slope, horizontal, and curvilinear sections, and a corresponding number of vibrators is required. This increases additional power consumption, and for routings of several changes of transportation directions it makes impossible the use of vibro-fluidizing because a combination of several vibrators, vibrating in different direction in the same pipeline is enough problematic.
Engineering problem of claimed invention consists in increase of transportation distance of bulk materials of high mass concentrations in case of low power consumption.
Engineering problem to solve is achieved that in method of vacuum-pneumatic transportation of bulk materials of high mass concentrations wherein bulk material is transported through a transporting pipeline from original zone of atmospheric pressure into intake zone, which is under vacuum, and according to the invention, vacuum in intake zone is created by alternate actions of impulses from one of two or more vacuum receivers, each of which is connected to a continuous vacuum source in such a manner that while vacuum impulse acting from one of the receivers on intake zone, this receiver synchronically, for the vacuum action duration period, disconnects from continuous vacuum source and the following receiver connects to continuous vacuum source. Number of receivers is determined by pipeline length and the directions of different sections thereof.
Proposed combination of features of claimed invention will allow ensuring the transportation of bulk material particles of high mass concentrations and low speeds through long length sections including ones containing elements, which change the transportation direction while simultaneous lowering of power consumption.
This is achieved by ensuring of stable support of required mass concentration over pipeline cross-section, because it allows performing fluidization of bulk material along some sections of pipeline avoiding break-downs. Impact of vacuum impulses on intake zone air forms pressure drop front, which spreads along all transportation channel and supports the bulk material in fluidized state of homogeneous concentrations over channel cross-section, compensating the loss of particles speeds and ensuring the transportation through long length pipeline sections. Periodical repetition of this action will allow ensuring the continuity of transportation process.